Re: [PATCH V8 2/3] irq: Track the interrupt timings

From: Thomas Gleixner
Date: Thu Mar 23 2017 - 17:17:47 EST


On Thu, 23 Mar 2017, Nicolas Pitre wrote:
> Is there a need for 64 bits of relative time stamps?
> And 32 bits of IRQ number?

No.

> I'd say that 48 bit time stamp and 16 bit IRQ number is way sufficient.
> Who cares if we mispredict an IRQ after 78 hours of idle time?
>
> Hence:
>
> u64 value = (ts << 16) | irq;

Excellent!